This invention generally relates to tuning mechanisms for a tunable receiver and more particularly to an improved tuning indicating system for a radio receiver or the like.
Usually radio tuning displays having tuning scales which correspond to each of the different wavebands which a radio can be tuned and is accomplished by a frequency indicating pointer operable by pushbuttons or a manual tuning knob. With the advent of improvements to tuners and band frequency displays, it has been found that the existing systems are not all together satisfactory from the standpoint of display especially in automobiles during darkness.
In accordance with the instant invention, an improved band frequency indicating system is provided which is simple and inexpensive and yet reliable. Generally speaking, the invention is accomplished by projecting a beam of light towards a dial scale corresponding to the frequency selected by an operator. While light beams have been used as indicating devices in the past as shown, for example, by U.S. Pat. No. 1,894,111 describing a light beam instrument and U.S. Pat. No. 2,138,875 describing a light beam for the purpose of theme finder, these devices do not encompass the particular structure or function or result obtained from the instant invention which is for the purpose of providing a band frequency indicating system for a radio receiver or the like. Furthermore, U.S. Pat. No. 2,081,746 describes a tuning device in which a light beam is used as a visual indicating device in a radio receiver, but this device relies upon the rotation of a scale past a fixed beam of light and is altogether different from the operation of the instant invention as will be more fully understood hereinafter.